Concrete pipe construction



Jan. 11, 1966 M. PACELLA CONCRETE PIPE CONSTRUCTION Original Filed Nov. '7. 1960 United States Patent 3,228,425 CONCRETE PIPE C(BNSTRUCTION Michael Pacella, 25 Fay Road, Dedhain, Mass. Continuation of application Ser. No. 67,551, Nov. 7, 1960. This application Jan. 9, 1964, Ser. No. 341,159

, 3 Claims. (Cl. 138--176) This application is a continuation of my co-pending application Ser. No. 67,551, filed Nov. 7, 1960, now abandoned.

This invention relates to an improved reinforced concrete pipe construction, and more particularly to a pipe joint therefor.

Reinforced and pre-stressed concrete pipe constructions have been known and widely used for many years, particularly for conducting and delivering water under high pressure to municipalities. Constant problems have been to provide such reinforced concrete pipe having sufficient strength to conduct the water, and other liquids, under the high pressures required, and at the same time to provide such pipe at reasonable cost, and to permit the ready assembly and installation of pipe sections on the job, and particularly to prevent leakage from the pipes at their joints. Such concrete pipe constructions have been reinforced by means of steel cylinders embedded within the concrete walls of the pipe, and prestressed by means of circumferentially or spirally Wound wires, wound under tension around either the steel cylinder or the concrete core of the pipe.

I have sought to provide an improved reinforced concrete pipe construction, and particularly a pipe joint therefor, having all the advantages and meeting the requirements of such reinforced concrete pipe constructions, as above set forth, and at the same time having many advantages of its own over such prior constructions. Particularly I have sought to provide a pipe and joint construction having an improved wire anchoring device, which reinforces the pipe construction in the bell area, and by reducing the number of turns of wire needed in the bell area avoids excessive pre-stressing of the pipe in the bell area, and thereby avoids the damage due to cracking and breakage caused by excessive prestressing in the bell area of the pipe.

Other objects and advantages of my invention will be seen in the attached drawing and following specifications of the pipe construction comprising my invention, in which:

FIG. 1 is a longitudinal sectional view through the joint, or connecting bell and spigot ends of my pipe construction.

In the drawing represents the core of the pipe, which comprises an inner and outer portion 10:: and 10b respectively, separated by the steel cylinder 12 and between which the steel cylinder 12 is embedded. The steel bell ring 14 and steel spigot ring 16 are welded to the bell and spigot ends of the steel cylinder 12, which ends of the pipe are denoted 18 and 20 respectively, and in the drawing are shown connected in a joined section, with the spigot end 20 inserted or telescoped within the bell end 18, and on its outside abutting it. Normally, the inner core 10a is first cast on the steel cylinder 12, within an inner cylindrical form, not shown, by standing the steel cylinder 12 in a vertical position, and inserting an inner forming cylinder not shown and casting concrete between the two cylinders. The inner form is then collapsed and removed when the concrete has attained sufiicient strength. This method is known as vertical casting. As an alternative method, the casting may be done centrifugally by holding the steel cylinder 12 in a horizontal position and rotating the cylinder about its central longitudinal axis, while concrete is deposited on the interior by centrifugal force. The outer core por- 3,228,425 Patented Jan. 11, 1966 "ice tion 19b outside the steel cylinder 12 may also be vertically cast by means of a cylindrical outer form, which is then removed, or it can be pneumatically applied as the cylinder 12 and inner core 12a are rotated. It will also be understood that inner and outer cores 10a and 1% can be formed within outer and inner forms at the same time, which forms are then collapsed and removed.

A bell grip 25 comprising a continuous steel band, essentially cylindrical in shape is embedded in the outer core 10b, with its outer surface approximately flush with the outer surface of outer cord 10b. The bell grip 25 may contain one or more corrugations as shown at 26, or other suitable serrations or irregularities on its inner surface, to prevent slippage of the bell grip 25 relative to the core ltlb. The bell grip 25- is made in any suitable manner. One satisfactory method is to cut a piece of required size from a flat sheet of steel plate, and coldroll it between suitable rollers into the desired cylindrical shape, and butt-weld the ends together to make a continuous band. The bell grip 25 is held in position while the outer portion 10b of the core is placed by temporary attachment to the exterior form or by other appropriate means. A spigot grip 30 similar to hell grip 25 is then placed on the spigot end of the pipe in similar fashion.

A steel wire 28 is then tightly wound under tension spirally around the outer portion 10b of the core 10 and is anchored at one end to the bell grip and at its opposite end to the spigot grip 30 in any suitable fashion, as by a standard mechanical grip device (not shown), several of which are available on the market and which itself is welded to the bell grip 25 and spigot grip 30. Another means is to provide a hole or groove in the bell grip 25 and spigot grip 30 for mechanically gripping the wire. The high tensile steel wire is Wound around the outside of the core 10 at a predetermined stress, by equipment specially designed for the purpose and available. The tightly wound steel wire 28 thus holds the core end of the pipe under compression and greatly increases the internal strength of the concrete pipe, to which the name pro-stressed concrete pipe is applied. Then the outer wall 32 of dense concrete with its enlarged bell end 18 and spigot end 20 is then applied, preferably pneumatically as the pipe is rotated, to provide an outer covering to protect the wires. Then a pre-formed annular rubber gasket 35 is provided with a suitable complementary circumferential groove on the spigot ring 16 to provide a water tight seal. Then two sections of pipe are joined together by inserting the spigot end 20 within the bell ring 14, as shown in FIG. 1 and the space between the joints is filled with a mortar or other suitable sealing compound to finish off the joints.

In this manner I have provided an improved reinforced and pre-stressed concrete pipe construction, having a reinforced bell area, which is much stronger and less likely to be chipped, cracked or broken, which provides a more satisfactory and stronger means for fastening the wire anchoring, and by means of which the number of necessary turns of the wire is reduced and at the same time avoids excessive pre-stressing in the bell area of the pipe.

I claim:

1. A reinforced concrete pipe construction comprising pipe sections each having a core portion comprising a longitudinally extending metal cylinder, a metal bell ring attached to said metal cylinder at the bell end of said pipe section, a metal spigot ring attached to said metal cylinder at the spigot end of said pipe section, and an inner and an outer concrete lining of substantial thickness covering said cylinder and a substantial portion of both said bell ring and said spigot ring, a cylindrical metal band closely surrounding said outer concrete lining of said core at a position to overlie at least a portion of said bell ring, a second cylindrical metal band closely surrounding said outer concrete lining at a position to overlie at least a portion of said spigot ring, a metal wire spirally Wound under tension around said outer lining and around each said band from one said band to the other of said band with the respective ends of said wire anchored on the corresponding said band, and an outer concrete wall completely covering said wire and said bands whereby said wire and said bands are entirely out of contact with the metal portions of said core, and with the corresponding portions of adjoining sections.

2. A concrete pipe construction as claimed in claim 1 wherein said metal bands are embedded in the outer surface of the outer concrete lining of said core.

3. A concrete pipe construction as claimed in claim 2 wherein the metal band at least at the bell end of said section is provided with at least one peripheral corrugation to prevent slippage of said band relative to said core.

References Cited by the Examiner UNITED STATES PATENTS 922,480 5/1909 Hodge 285-288 X 1,048,045 12/1912 Cronholm 285288 2,138,946 12/1938 Trickey 285-288 X 2,325,469 7/1943 Boissou 285288 2,576,012 11/1951 Gurck 285288 2,805,683 9/1957 Kennison l38-176 X LAVERNE D, GEIGER, Primary Examiner.

EDWARD V. BENHAM, Examiner. 

1. A REINFORCED CONCRETE PIPE CONSTRUCTION COMPRISING PIPE SECTIONS EACH HAVING A CORE PORTION COMPRISING A LONGITUDINALLY EXTENDING METAL CYLINDER, A METAL BELL RING ATTACHED TO SAID METAL CYLINDER AT THE BELL END OF SAID PIPE SECTION, A METAL SPIGOT RING ATTACHED TO SAID METAL CYLINDER AT THE SPIGOT END OF SAID PIPE SECTION, AND AN INNER AND AN OUTER CONCRETE LINING OF SUBSTANTIAL THICKNESS COVERING SAID CYLINDER AND A SUBSTANTIAL PORTION OF BOTH SAID BELL RING AND SAID SPIGOT RING, A CYLINDRICAL METAL BAND CLOSELY SURROUNDING SAID OUTER CONCRETE LINING OF SAID CORE AT A POSITION TO OVERLIE AT LEAST A PORTION OF SAID BELL RING, A SECOND CYLINDRICAL METAL BAND CLOSELY SURROUNDING SAID OUTER CONCRETE LINING AT A POSITION TO OVELIE AT LEAST A PORTION OF SAID SPIGOT RING, A METAL WIRE SPIRALLY WOUND UNDER TENSION AROUND SAID OUTER LINING AND AROUND EACH SAID BAND FROM ONE SAID BAND TO THE OTHER OF SAID BAND WITH RESPECTIVE ENDS OF SAID WIRE ANCHORED ON THE CORRESPONDING SAID BAND, AND AN OUTER CONCRETE WALL COMPLETELY COVERING SAID WIRE AND SAID BANDS WHEREBY SAID WIRE AND SAID BANDS ARE ENTIRELY OUT OF CONTACT WITH THE METAL PORTIONS OF SAID CORE, AND WITH THE CORRESPONDING PORTIONS OF ADJOINING SECTIONS. 